Hi all, as the title suggests i think i need to get a bit more power on my 1100 ado 16 to cope with modern day traffic as a daily. Thinking of maybe 295 head and single 1 1/2 SU. Looking for advice on inlet and exhaust manifold plus what type of exhaust would suit this set up. My thoughts are that the cast combined inlet/ exhaust manifold would only allow use of the original exhaust which may restrict flow. Any advice welcome as i,m really no expert on such matters, cheers Tim

The 295 head and a single HS4 would work well, and this should allow you to keep a standard factory air filter set-up. If you use a standard factory HS4 cast iron manifold (is yours HS2?) then probably the simplest option is to fit a 'magic pipe' which can fit straight onto the standard manifold and is sized to allow RC40 exhaust system to be fitted.

If you go for a separate inlet manifold there are a lot of aftermarket ones out there, would suggest looking for one that is sized for 1.5 inch carb not 1.75, and puts the carb at the correct angle for the air filter set-up. Might be possible to separate a factory cast iron manifold and just use the inlet part, but not sure this will allow enough clearance for the centre exhaust downpipe. If you do go for separate inlet/exhaust manifolds then the exhaust downpipe I would recommend is the Maniflow Freeflow. It works well, should clear the driveshaft rubber output couplings, and is a lot less hassle to install than a LCB.

And for exhaust pipe and silencers I think the side exit twin box RC40 could be made to fit? Might be a bit of a tight fit next to the sandwich plate that holds the alloy remote to the gearbox, and you will need a bit more length than a Mini. I was going to fit a twin box RC40 to my 1300GT many years ago, but it failed the MOT major style so this upgrade never happened...

I used to run a twin box RC40 in the past in my 1100, but the only way to fit it reasonably was with the resonator in the usual position of the silencer in the tunnel, and the second oval box fitted sideways under the boot, with the tailpipe having a nearside exit. In fact, this is the standard 1300 GT set up, regarding the exhaust fitment, so it's not too bad. Of course with a fitment like this we had to bend and weld some new tubes; An off the shelf RC40 system doesn't fit under an ADO16. I kept it fore some years without any problems, but then i decided that i liked more the centre exit, so i had a couple of custom silencers tailor made to fit under the tunnel. The truth is that even for the standard engine the exhaust is very restrictive, so you should do something about it. And this does not mean that the new system will be necessarily any louder. With the rest of the modifications it is more or less what was already described. A maniflow Freeflow will fit, but with some hammer massage at the Y in order to avoid hitting the subframe. Also the tail of the freeflow does not come at an ideal angle relative to the remote alloy housing. Finally, if you intend to move further than simple bolt-on mods, perhaps you should consider a different camshaft and (depending on your driving style) a taller final drive ratio. IMHO the 4.1:1 is too low even for a standard 48 bhp engine.

12G295 head skimmed to bring the CR up to 9.5:1, 1.5 inch SU carb on a standard manifold, standard exhaust manifold is okay with a 1300 exhaust and a 270 camshaft - or the modern equivalent off the 997 Cooper cam with a pin drive. The Kent Megadyne as developed by Dave Vizard works very well.

Most importantly though is to get it set up on a dyno with a properly calibrated distributor and carb jetting - Aldon Engineering or Steve Harris are about your best bet from memory, maybe Southam Mini Centre of they're still going.

Many thanks for all your reply.s fellas. I think the Magic Pipe looks a good option with a H4 cast manifold, of which I already have. I haven't got loads of money to throw at it so this looks like the cheapest option. As for the exhaust, I had looked at the mani flow system and I assume the magic pike would fit this okay ?. The head has already been skimmed I believe but will check measurements when I dig it out. Once again thanks for all your advice, cheers Tim

Who is online

Users browsing this forum: No registered users and 5 guests

You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forumYou cannot post attachments in this forum